
1-11
Power Connection Considerations
The following questions and explanations will help you determine how to supply 24VDC power to the
North American Operator Panel.
1. Is the CNC an “Open CNC System? That is, is it a system containing an integrated personal computer
(PC) or an external PC with High-Speed Serial Bus (HSSB) hardware?
If your answer is yes, the power-down sequence must include the time required to shut down the
computer’s Operating System before physically disconnecting power from the PC. A timing sequence
run from the PMC ladder diagram can be used to accomplish this. Use the OFF pushbutton to start the
sequence. For more information, refer to your Open System documentation.
2. Which CNC or motion control product is involved – Series 15i, Series 16i/18i, Series 21i CNC, or
Power Mate i Models D and H?
For Series 16i/18i and 21i power connections, refer to Pages 1-13 and 1-14. For Power Mate i Models
D and H power connections, refer to Page 1-15. For Series 15i power connections, refer to Page 1-18.
3. Is the Series 16i/18i/21i CNC an LCD-Mount or Stand-Alone system?
Separate wiring diagrams are provided on Pages 1-13 and 1-14 for these different configurations.
4. Is it desirable to isolate the 24VDC power supplied to the CNC from the 24VDC power supplied to the
Machine I/O, including the North American Operator Panel?
Due to resistive or inductive loading by 24VDC external machine devices, it may be beneficial to use a
separate power supply to drive such loads. The machine tool builder must determine this and
implement the appropriate wiring diagram to suit each application.